<p>This entry contains <taxon tax_id="83333">Escherichia coli</taxon> (strain K12) YfbR. It is a 5'-deoxynucleotidase that functions as a dCMP phosphohydrolase in a salvage pathway for the synthesis of dUMP in a dcd/deoA mutant [<cite idref="PUB00053957"/>]. YfbR contains a conserved HD domain [<cite idref="PUB00034504"/>]. YfbR has phosphatase activity with deoxyribonucleoside 5'-monophosphates and does not hydrolyze ribonucleotides or deoxyribonucloside 3'-monophosphates [<cite idref="PUB00034504"/>]. Nucleotidase activity of YfbR was discovered in a high-throughput screen of purified proteins [<cite idref="PUB00053777"/>]. Crystal structures of YfbR have been solved; based on an analysis of crystal packing and size-exclusion chromatography, it was suggested that the biological unit is a dimer. Site-directed mutagenesis confirmed the importance of certain conserved active site residues, and mechanisms for substrate selectivity and catalysis were proposed [<cite idref="PUB00048646"/>].</p> dCMP phosphohydrolase